Featural versus configural face processing in a rare genetic disorder: Williams syndrome

Local vs global processing in Williams syndrome

BACKGROUND

It has long been debated whether in Williams syndrome (WS) there is a preferential processing of local with respect to global forms, in contrast to the typical 'global advantage' in healthy individuals, which in WS seems to exist only for faces.

AIMS

We aimed at verifying it and to assess the role of stimulus familiarity by comparing performances with faces to those with other objects using the same type of task.

METHODS AND PROCEDURE

A group of children and adolescents with WS and controls with typical development performed a modified version of three tasks: Mooney (with faces and/or guitars), Jane (with faces and houses) and Navon task.

OUTCOMES AND RESULTS

Individuals with WS were able to process at a global level not only faces but also objects, although they were impaired when they had to compare or discriminate between two stimuli. All groups showed an advantage for global processing, with familiarity improving it. However, WS participants did not benefit from familiarity as much as typically developing young individuals.

CONCLUSIONS AND IMPLICATIONS

Peculiar abilities for face stimuli in WS did not emerge nor did a clear facilitation related to object familiarity. These results are useful for planning effective interventions.

Brief Report: The Impact of Sensory Hypersensitivity and Intolerance of Uncertainty on Anxiety in Williams Syndrome

This study explored the interrelationship between intolerance of uncertainty, sensory hyper-sensitivity and anxiety in Williams syndrome (WS). Thirty-two parents or guardians of individuals with WS (M_age = 24.76 years, SD = 7.55) were included. Associations between anxiety, intolerance of uncertainty, sensory hyper-sensitivity, and ASD symptoms were assessed. Linear regression analysis revealed that intolerance of uncertainty and sensory hyper-sensitivity were unique independent predictors of anxiety, while social communication score was not. There was evidence of a mediating effect of sensory hyper-sensitivity on the relationship between intolerance of uncertainty and anxiety. These findings bear strong resemblance to the pattern seen in ASD and emphasize the need for development of anxiety interventions that attempt to reduce negative beliefs about unpredictable situations in WS.

The temporal unfolding of face processing in social anxiety disorder--a MEG study

The current study is the first to use magnetoencephalography (MEG) to examine how individuals with social anxiety disorder (SAD) process emotional facial expressions (EFEs). We expected that, compared to healthy controls (HCs), participants with SAD will show an early (<200 ms post-stimulus) over-activation in the insula and the fusiform gyrus (FG, associated with the N170/M170 component), and later (>200 ms post-stimulus) over-activation in the dorsolateral prefrontal cortex (DLPFC). Individuals with SAD (n = 12) and healthy controls (HCs, n = 12) were presented with photographs of facial displays during MEG recording. As compared to the HC group, the SAD group showed a reduced M170 (right FG under-activation around 130–200 ms); early reduced activation in the right insula, and lower insular sensitivity to the type of EFE displayed. In addition, the SAD group showed a late over-activation in the right DLPFC. This unique EFE processing pattern in SAD suggests an early under-activation of cortical areas, possibly related to reduced emphasis on high spatial frequency information and greater early emphasis on low spatial frequency information. The late DLPFC over-activation in the SAD group may correlate to failures of cognitive control in this disorder. The importance of a temporal perspective for the understanding of facial processing in psychopathology is underlined.

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This study is the first to use MEG to study social anxiety disorder (SAD).

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SADs and controls viewed emotional facial expressions during MEG.

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Compared to controls, SADs showed reduced M170 (early fusiform gyrus activity).

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SADs presented a late over-activation in the right dorsolateral prefrontal cortex.

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The late frontal over-activity may correlate to failures of cognitive control in SAD.

Linking social behaviour and anxiety to attention to emotional faces in Williams syndrome

The neurodevelopmental disorder Williams syndrome (WS) has been associated with a social phenotype of hypersociability, non-social anxiety and an unusual attraction to faces. The current study uses eye tracking to explore attention allocation to emotionally expressive faces. Eye gaze and behavioural measures of anxiety and social reciprocity were investigated in adolescents and adults with WS when compared to typically developing individuals of comparable verbal mental age (VMA) and chronological age (CA). Results showed significant associations between high levels of behavioural anxiety and attention allocation away from the eye regions of threatening facial expressions in WS. The results challenge early claims of a unique attraction to the eyes in WS and suggest that individual differences in anxiety may mediate the allocation of attention to faces in WS.

Contextual integration of causal coherence in people with Williams syndrome

This study investigated causal coherence in people with Williams syndrome (WS). To advance our understanding of this clinical group, we examined their ability to make causal inferences, using their understanding of homonyms (words with the same spelling but distinct meanings) embedded in contexts. A minor goal was to use verbal stimuli to clarify Santos and Deruelle's (2009) findings on the knowledge of causality among people with WS. Participants were presented with two types of scenarios requiring different inference directions: backward inferences (from consequence to cause) and forward inferences (from cause to consequence). Following each scenario, they were asked a comprehension question and given three possible answers that corresponded to a figurative, literal, and unrelated meaning of the homonym embedded in the scenario. The correct answer required the participants to make a successful causal inference. People with WS aged from 13 to 29 (n=17, mental age=6-14) were able to make backward and forward inferences by selecting the context-appropriate meanings of homonyms, thus demonstrating the existence of contextual integration ability in the causal coherence of people with WS. However, as their accuracy in the figurative meaning responses was lower than that of healthy age-matched controls, suggesting the participants with WS, were delayed in the contextual integration of causal coherence. The participants with WS chose a significantly higher percentage of answers with unrelated meanings than the two control groups, indicating a certain degree of weakness in the contextual integration of homonyms in context.

Social brain development in williams syndrome: the current status and directions for future research

Williams syndrome (WS) is a neurodevelopmental condition that occurs as a result of a contiguous deletion of ∼26–28 genes on chromosome 7q11.23. WS is often associated with a distinctive social phenotype characterized by an increased affinity toward processing faces, reduced sensitivity to fear related social stimuli and a reduced ability to form concrete social relationships. Understanding the biological mechanisms that underlie the social phenotype in WS may elucidate genetic and neural factors influencing the typical development of the social brain. In this article, we review available studies investigating the social phenotype of WS throughout development and neuroimaging studies investigating brain structure and function as related to social and emotional functioning in this condition. This review makes an important contribution by highlighting several neuro-behavioral mechanisms that may be a cause or a consequence of atypical social development in WS. In particular, we discuss how distinctive social behaviors in WS may be associated with alterations or delays in the cortical representation of faces, connectivity within the ventral stream, structure and function of the amygdala and how long- and short-range connections develop within the brain. We integrate research on typical brain development and from existing behavioral and neuroimaging research on WS. We conclude with a discussion of how genetic and environmental factors might interact to influence social brain development in WS and how future neuroimaging and behavioral research can further elucidate social brain development in WS. Lastly, we describe how ongoing studies may translate to improved social developmental outcomes for individuals with WS.

A comparison of facial emotion processing in neurological and psychiatric conditions

Patients suffering from various neurological and psychiatric disorders show different levels of facial emotion recognition (FER) impairment, sometimes from the early phases of the disease. Investigating the relative severity of deficits in FER across different clinical and high-risk populations has potential implications for the diagnosis and treatment of these diseases, and could also allow us to understand the neurobiological mechanisms of emotion perception itself. To investigate the role of the dopaminergic system and of the frontotemporal network in FER, we reanalyzed and compared data from four of our previous studies investigating FER performance in patients with frontotemporal dysfunctions and/or dopaminergic system abnormalities at different stages. The performance of patients was compared to the performance obtained by a specific group of matched healthy controls using Cohen’s d effect size. We thus compared emotion and gender recognition in patients with frontotemporal dementia (FTD), amnestic mild cognitive impairment (aMCI), Alzheimer’s disease (AD) at the mild dementia stage, major depressive disorder, Parkinson’s disease treated by l-DOPA (PD-ON) or not (PD-OFF), remitted schizophrenia (SCZ-rem), first-episode schizophrenia treated by antipsychotic medication (SCZ-ON), and drug-naïve first-episode schizophrenia (SCZ-OFF), as well as in unaffected siblings of patients with schizophrenia (SIB). The analyses revealed a pattern of differential impairment of emotion (but not gender) recognition across pathological conditions. On the one hand, dopaminergic medication seems not to modify the moderate deficits observed in SCZ and PD groups (ON vs. OFF), suggesting that the deficit is independent from the dopaminergic system. On the other hand, the observed increase in effect size of the deficit among the aMCI, AD, and FTD groups (and also among the SIB and SCZ-rem groups) suggests that the deficit is dependent on neurodegeneration of the frontotemporal neural networks. Our transnosographic approach combining clinical and high-risk populations with the impact of medication provides new information on the trajectory of impaired emotion perception in neuropsychiatric conditions, and on the role of the dopaminergic system and the frontotemporal network in emotion perception.

Preliminary evidence of abnormal white matter related to the fusiform gyrus in Williams syndrome: a diffusion tensor imaging tractography study

Williams syndrome (WS) is a genetic condition caused by a hemizygous microdeletion on chromosome 7q11.23. WS is characterized by a distinctive social phenotype composed of increased drive toward social engagement and attention toward faces. In addition, individuals with WS exhibit abnormal structure and function of brain regions important for the processing of faces such as the fusiform gyrus. This study was designed to investigate if white matter tracts related to the fusiform gyrus in WS exhibit abnormal structural integrity as compared to typically developing (TD; age matched) and developmentally delayed (DD; intelligence quotient matched) controls. Using diffusion tensor imaging data collected from 40 (20 WS, 10 TD and 10 DD) participants, white matter fibers were reconstructed that project through the fusiform gyrus and two control regions (caudate and the genu of the corpus callosum). Macro-structural integrity was assessed by calculating the total volume of reconstructed fibers and micro-structural integrity was assessed by calculating fractional anisotropy (FA) and fiber density index (FDi) of reconstructed fibers. WS participants, as compared to controls, exhibited an increase in the volume of reconstructed fibers and an increase in FA and FDi for fibers projecting through the fusiform gyrus. No between-group differences were observed in the fibers that project through the control regions. Although preliminary, these results provide further evidence that the brain anatomy important for processing faces is abnormal in WS.